Apparatus for handling liquids



28, 1944. w BAKER APPARATUS FOR HANDLING LIQUIDS Original Filed Aug. 4 1940 2 Shee'ts-Sheet 1 Bnnentor W/LLm/ E, BHKEK.

Gttom eg March 28, 1944. 'w BAKER APPARATUS FOR HANDLING LIQUIDS Original Filed Aug. 4, 1940 2 Sheets-Sheet 2 Snnentor W/LL/HM 5. EHKEK Ottorneg Patented Mar. 28, 1944 arranuus ron HANDLING mourns William E. Baker, Swanton, Ohio Original application August 4, 1940, Serial No.

351,356. Divided and "I18 1942, Serial No. 444,101 10 Claims. (oi. 103-162) The present invention relates broadly to the handling of liquids and more particularly to im provements in pumping liquid fuel.

This application is a division of my copending application Serial No. 351,356, filed August 4, 1940.

In the original case there is set forth a complete process and apparatus for the handling,

v conditioning, and combustion of liquid fuel and certain portions of the apparatus described therein are of such a nature that they can be 'used satisfactorily for purposes other than liquid fuel combustion. This divisional application is being filed to cover and claim subject-matter which can not be claimed in the parent application, namely, that relating to the handling or circulating portion per se of the system.

Broadly speaking, my system may be divided into three phases: 1) circulation of the raw oil from a reservoir to the atomizing or mistifying equipment; (2) the atomization of the oil involving breaking down, and mixing thereof with air and delivery of the oil-air mixture; and (3) combustion of the oil-air mixture including, as a preferable feature, the addition of so-called secondary air at or in the region of the point of combustion.

Each of the three phases of my system includes novel features and, when combined, give a system that permits burning of various grades of fuel oil. Speaking in generalities, the problem of burning the more highly refined fuel oils is not as difficult as burning of the relatively cheaper grades which are not as well or highly refined. The cheaper and poorer grades of fuel oil heretofore have presented certain difiiculties as to pumping, atomization, and combustion which have discouraged the use of such cheaper grades of oil for general domestic and industrial heating, except in those cases where proper and almost constant maintenance could be provided for necessary cleaning and other matters making it possible to use the cheaper grades of oil. As is generally known, in the domestic field, such as oil burning equipment for homes, burners have been designed to handle N0. 3 oil. No. 5 oil is substantially cheaper than No. 3 oil, but the ordinary burner designed for handling No. 3 oil will not give satisfactory service with No. 5 oil, because, in addition to inability to handle the cheaper and dirtier, heavier oil, said equipment does not give sufficient or proper atomization of the oil. Furthermore, when the ordinary 3 oil burner is furnished with Soil, the burner nozzle or tip cokes up in a relatively short time, with extremely unsatisfactory results if not failure of the unit.

application May 2,7,

This invention is concerned with the circulating phase of my system and provides a combined circulating and metering pump. That is. thepump system withdraws liquid fuel from the tank or reservoir and pumps itcontinuously past the metering portion of the pump and returns the unused volume back to the tank or reservoir. While the excess may be controlled as desired, in the smaller type units I circulate from two to two and one-half times the oil past the metering part of the pump as is withdrawn by the metering pump and directed toward the atomizing portion of the equipment. In larger units where a greater volume of oil or fuel is consumed, it is not necessary, for satisfactory results, to circulate such a large excess, although in all cases I prefer to pump from the tank more oil than is required. The reason for pumping the excess oil is to avoid surging, air entrapment, or a deficiency of oil which would interfere with proper operation of the system as a whole. Another advantage in pumping this excess oil resides in the fact that a continuous, steady supply of oil is at all times available for the atomizing section during operation thereof. It will of course be understood that fluctuations in the oil supply or presence of air in the'line presents a diillculty in holding a constant fire. Even assuming that the exact amount of oil could be furnished for any given viscosity, I have found that the viscosity of any given grade of oil varies enough to throw any preselected conditions out of balance, so that to safeguard against variations in oil viscosities and the other factors just mentioned, I consider the pumping of excess oil to and past the metering section to be of vital importance. It is important not only from the angle of proper operation but also as a safety factor, avoiding as it does the possibility of too much fire or too little fire and danger of explosions. As a matter of convenience, it is wise to keep air out of the line because if there is a lack of oil supply, the safety control will kick out, necessitating manual resetting.

Although the circulating portion of the pump handles an excess of oil, measured amounts only are permitted to flow to the mixing or atomizing portion. The pump unit is adjustable to vary not only the amount of oil circulated but also the metering section so that a predetermined measured volume of oil is caused to be pumped to the atomizer.

For purposes of this application, No. 3 oil will be considered as representing a high grade, well it will of course be understood that fuel oil is used herein by way of example rather than limitation, as it is intended that the Word *oil-will include any fluid.- As a practical matter, commercial No. oil is extremely poor quality yvith relation to No.3 oil. Because'it is a heavier oil, it has a higher 13. t. u. rating per gallon than the No. 3 oil and this, coupled with its lower price, is indicative of the fact that if it can be used, heating costs will be substantially lower. The problem has been to find some satisfactory and reliable way of using the oil.

For sake of simplicity, as a specific application of my pump system, I have described its adaptation to a domestic heating plant. However, in no sense of the word is the system restricted to this particular field, and smaller or larger units can be made to handle more or less oil per hour.

Other objects and advantages of theinvention will become more apparent during the course .of the following description when taken in connection with the accompanying drawings.

In the drawings wherein like numerals are employed to designate like parts throughout the same:

Fig. 1 is a perspective view showing a complete pump unit;

Fig. 2 is a longitudinal, vertical section taken substantially on line 2-2 in Fig. 1;

Fig. 3 is a transverse section taken substantially on line 3-3 in Fig. 2; r

Fig. 4 is a transverse section taken substantially on line 4-4 in Fig. 2; and

Fig. 5 is a fragmentary vertical section taken substantially on line 5-4 m Fig. 2.

Referring to Fig. 1, it will be noted that the pumping and metering apparatus is compact and can be mounted upon any suitable support. The raw oil is drawn into the unit from the tank through the pipe 34.

As shown in Figs. 1 and 2, the main drive shaft- 25 of the apparatus carries the worm 35 meshing with the worm .wheel 35 keyed to the pump driving shaft 31 which rotates in the direction of the arrow shown in Fig. 3. In the particular pumping mechanism illustrated and as particularly shown in Figs. 3 and 4, there are four cylinders and four pistons, each piston, in eflect, being two pistons. Each of the pistons, designated in their entirety by the letter A, comprises the portion 38 and the relatively thicker portion 33. The part 38 is used for pumping and circulating the oil and the part 39 is used for the metering and pumping of the oil to the atomizing section. The pistons operate in the pump barrel or cylinder block 43. The stepped cylinders 51 formed in the barrel have a bore, a portion of which is of greater diameter than the other portion; that is, the end.of the bore receiving the part 33 of the piston A is of less diameter than that part of the bore receiving the piston end 39. In the apparatus illustrated, the diameter of the end 33 is approximately three-eighths of an inch and the diameter of the end 33 is approximately seven-sixteenths of an inch, which produces the shoulder 42 employed as a cylinder head of annular formation to take care of the metering and pumping of the metered oilto the atomizing section.

Roughly speaking, the cubic displacement of the end 43 of the piston is approximately two to two and one-half times the cubic displacement of the annular head 42 and as the two pistons operate together, it will be seen that the end 38 will have a greater displacement than the head 42, which makes it possible to circulate a slot formed in the barrel. Thereby, upon rotation of the shaft 3?, the barrel rotates at the same speed within the bushing pressed into the casing or housing at. The housing and bushing are of course stationary and are provided with suitable ports through which the oil is received and part of which is withdrawn by the metering end and pumped to the atomizing section. As shown particularly in Fig. 3, which is a. section o line 3-3 in Fig. 2, the circulating end of each of the cylinders has a port d'l extending outwardly through the barrel. The oil intake pipe 35 is fastened to the housing by means of a threaded boss 48 communicating with the port 19 extending through the housing 46. The port 49 is disposed in the same plane as the ports 41 formed in the barrel 4!! and communicating with the closed end of the cylinders M. The bushing 45 is provided with a slot 53 which extends from the point B in Fig. 3 to the point C. As will be explained later, operation of the pump causes the oil to flow in through the pipe 34 and to fill the groove in the bushing between the points B and C. A second groove 5! formed in the bushing 45 and in the same plane as the groove 50 extends from the point D to the point E as shown in Fig. 3. This groove 5i communicates with the passageway 52 which leads to the valve device 53.

In Fig. 2 is shown the means employed for operating the pistons. Pivotally mounted upon the end 54 of the housing is a thrust bearing 55 pivoted by means of the pin 56 and adjusted about its pivot point by the adjusting screw 51. A hardened ring member 58, having a ball-race 5B, is mounted upon the thrust bearing.

Each of the pistons, as shown in Fig. 2, is provided with a hardened end 60. Each of the pistons is preferably made from hardened steel and each has an end 69 adapted for contact with the face of the ring 58. The end 60 of each piston is, broadly speaking, cone shaped to correspond approximately to the operating angle of the disc 58.

The pistons are normally urged outwardly of the cylinder by means of coil springs 6| surrounding the pistons bearing at one end against the cylinder barrel and at the opposite end on thefiange 62, preferably formed as an integral part of the piston. 1

As shown in Fig. 2, the left-hand piston is in its wide open position and the right-hand piston is in its closed position.

To facilitate rotation of the cylinder barrel and associated parts, a roller bearing unit 63} The main function of the ball and detent construction is to assist in holding the oil seal parts together so that the oil seal, designated in its entirety by the. numeral 10, will function properly. As shown, a second spring H is effective upon the opposite end of the oil seal to likewise assist in holding the parts together. and the combined action of the two effectively prevents passage of oil through the oil seal.

Upon rotation of the shaft 91, the barrel is rotated and as the ring 99 is mounted in an inclined position, it will be seen that the pistons are caused to work in and out of theirrespective cylinders.

The pump is so timed that as each cylinder is moved past the groove 98, oil will be drawn into said cylinder. Then, upon continued movement of the barrel in the direction of the arrow in Fig. 3, each cylinder will be taken out of communication with the groove", slid past the land F and then brought into communication with the second groove II. In the meantime, as the piston is riding on the ring" forming an effective cam, it is moving within its cylinder and, when in communication with the groove each piston is at that part of the stroke causing forceful movement of the oil into the groove and through the passageway 52, and into the control valve assembly 88. It will of course be understood that each of the pistons, for example four, goes through the same cycle as the others, so that each of the individual pistons serves first to draw oil into the pump and each serves to force part of the oil into the valve 53.

In Fig. 3, the valve operating mechanism has been removed for sake of clarity. By comparing Figs. 2 and 3, it will be seen that the oil being pumped through the passageway 52 is received in the cavity 12. Mounted within the cavity 72 is a bellows type valve 13 carried by the screw cap ll threaded into the end of the opening as shown. The bellows valve carries the stem 15, at the opposite end of which is a self-aligning head 16 designed for cooperation with the needle valve ll. The stem 15 has a close fit through the bushing 18 and is such as to prevent oil leakage between the stem and bushing. However, there is sufficient clearance to permit reciprocation of the stem through the bushing, movement thereof being controlled by the oil itself acting upon the bellows valve.

When the unit is not in operation, the valve is closed. At the start of a cycle, the pump pumps the oil into the cavity 12, as has already been explained, and when adequate pressure has been built up, normally about two pounds per square inch, the bellows valve is compressed; that is, the end remote from the cap 14 is moved toward the cap which slides the stem through the bushing and lifts the end 18 from the valve ll.

Upon such movement of the valve, the port 19 formed transversely through the stem is moved beyond the end 80 of the bushing 18 and is thus brought into position where it may receive oil from the chamber 12. The stem is also provided with a second transverse port 8| disposed beneath the port 19 and the center of the stem is removed so that the two ports are in communication with one another through the passage 82 as shown in Fig. 2.

Thus, the oil flowing into the port 19 passes through the channel 82 and into the port 8|. Shown particularly in Figs. 4 and 5, the port 8| registers with the port 83 extending through the bushing and into the channelway 84. The oil then flows through this port into the conduit 85 formed through the bracket 86 which is a part of the pump housing, as clearly shown. The oil thus passes to the metering portion of the pump going into a groove 8! formed in the bushing 45, which groove extends from the point G to the point H in Fig. 4. This is the intake groove of the metering section and unused oil flows through the exhaust pipe 89 and is returned to the tank.

The so-called metering operation is handled by the thicker diameter portions of the pistons previously referred to as the parts 39. The parts 89 of course operate in the enlarged end of the cylinders and each enlarged end has a port 89 extending from the cylinder outwardly. For example, as shown in Fig. 4, the top cylinder of the figure is in communication with the groove 81 formed in the bushing.

It will be understood that the flow of oil' through the passageway 85 and groove 81 is induced by the pumping end 98 01' the pistons. .As each of the metering portions of the cylinders is in registration with the groove 81, some of the oil is drawn into the cylinder, depending, of course, upon the stroke of the piston which in turn is dependent upon the adjustment of the thrust bearing and ring previously described. As the cylinder barrel is rotated in the direction of the arrow in Fig. 4, the oil is drawn into the cylinder and is discharged therefrom in a groove disposed in the sleeve between points J and K. The groove 99 is in the same plane as the groove 81. It will be noted that there is a land between the points G and K. The oil discharged from each cylinder and received in the groove 90 is then caused to flow through the passageway 9| shown in Fig. 4 and thus conveyed or forced into the cavity 92 clearly illustrated in Fig. 2. By

further reference to Fig. 2, it will be noted that a cylindrical filtering screen 93 surrounds the bushing 18 so that oil coming from the metering pump is caused to pass through the screen and into the orifice 94 extending transversely through the bushing.

When the unit is not in operation, the selfaligning end 16 of the stem seats upon the needle valve 11 so that no flowing of oil is permitted to go through the conduit 95. However, when operating, the oil coming from the metering portion of the pump is received within the cavity 92, passes through the screen and into the orifice 94.

As previously mentioned, during pumping, the bellows valve has been caused to slide the stem so that the needle valve is opened and the oil permitted to flow through the bore 96 of the conduit 95 and on to the atomizing section.

When the unit cuts off and the pressure is relieved, the bellows valve slides the stem and associated parts in the opposite direction, which returns the port 19 to within the bushing, preventing further flow of oil therethrough and, likewise, the needle valve 11 is closed so that there is no further flow of oil to the pump or from the metering section.

In view of the fact that it is desirable to include suitable straining and filtering means between the tank and the pump, the screen 93 is used only as an'added precaution, but ordinarily this requires very little if any cleaning.

It will thus be seen that I have disclosed a pumping and metering device that will have a wide application wherever the handling of a constant and measured amount of fluid is desired.

It is important that the two pistons produced by having a single piston with different diameter sections be used, because in this way they have the same stroke and with no opportunity for one piston getting out of balance with the other. The ratio of pumping capacities is fixed by the relative displacement between the two sections and, in the particular illustration herein made, the

displacement of the pumping piston 38 is from two to two and one-half times that of the displacement of the metering piston 39.

With this arrangement and control of ports and use of the bellows valve, a constant excess supply of oil is at all times moved through the .port, from which the metering valve draws its measured supply of oil during operation of the apparatus. The same ratio between pumping of raw oil and metering is maintained, for, as the cam ring 58 is adjusted to furnishmore or less oil by the metering device of the atomizer, a corresponding increase or decrease of oil is pumped by the pistons 38.

Because of the presence of an abundance of oil in the groove 81, thereis always more oil present than can possibly be drawn into the metering cylinder during the time that any given cylinder is in registration with said oil groove.

It will be noted that four cylinders have been illustrated in the pump unit. There is nothing critical about the number of cylinders and pistons which can be employed. As previously stated,

the use of four cylinders has provendesirable as a minimum because a uniform, even flow of material is obtained. However, as units of increased capacity are made, it is preferable to increase the number of cylinders and pistons to get the desired added capacity. This is preferable to merely increasing the diameter of the cylinders. I have personally constructed'unlits with sixteen cylinders for forty gallon an hour burners, and if still larger units are desired the number of cylinders can be further increased. The same principles and same mode of operation are used with the larger units as is used with the unit completely described in detail in this application. In the main, the working parts are lubricated by the fuel itself, but it will be understood that external shafts and parts which do not come in contact with the fuel can be lubricated in the ordinary manner.

There have been many objections in the art to the use of N01 5 oil, especially for domestic purposes. One diiiiculty encountered has been bleeding of the lines or the system, permitting air to enter which may result in a throw-out of the safety device or failure to gain ignition. The danger of bleeding is overcome in connection with'my pump because when'the bellows valve closes (Fig. 2), it traps the oil in the line, so that the line is always full of oil.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same and that various changes in the shape, size and arrangement of parts may be resorted. to without departing from the spirit of the inven tion or the scope of the subjoined claims.

I claim:

1. A pump unit of the character described, comprising a pumping section of relatively large pumping capacity and a metering section of relatively smaller pumping capacity, an inlet passageway connecting said pumping section with a source of liquid supply, a return passageway leading from said pumping section past said metering section to said source of liquid supply, an outlet passageway connecting "said metering section with a point of delivery, means within said pumpingsection for pumpingdiquid from the source of supply past the metering section and back to said source of supply, means within said metering section for withdrawing a predeterpredetermined point and for closing said valves when the pressure falls below said predetermined point.

2. A pump unit of the character described, comprising a pumping section of relatively large pumping capacity and a metering section of relatively smaller pumping capacity, an inlet passageway connecting said pumping section with a. source of liquid supply, a return passageway leading from said pumping section past said metering section to said source of liquid supply, an outlet passageway connecting said metering section with a point of delivery, means within said pumping section for pumping liquid from the source of supply, means within said metering section for withdrawing a predetermined amount of liquid from said return passageway and directing it to said point of delivery, a valve in the return passageway between said pumping section and said metering section, a second valve in said outlet passageway, and means responsive to the pres sure of the liquid in the return passageway leading from said pumping section for opening said valves when such pressure rises to a predetermined point and for closing said valves when the pressure falls below said point.

3. A pump unit of the character described, comprising a cylinder block provided with a plurality of stepped cylinders having ports at each step, a two-part piston operating within each of said cylinders, one part of each of said pistons having a relatively greater pumping capacity and constituting the pumping section of the unit and the other part of each piston having a relatively smaller pumping capacity and constituting the metering section of the unit, an inlet passageway connecting said pumping section with a source of liquid supply, a return passageway leading from said pumping section past said metering section to said source of liquid supply, an outlet passageway connecting said metering section with a point of delivery, means for reciprocating said pistons, and means functioning in timed relation with the reciprocation of said pistons for placing the ports withdraw a measured portion of said liquid into the metering section and direct it to said point of delivery.

4. A pump unit of the character described, comprising a cylinder block provided with a plurality of stepped cylinders having ports at each step, a two-part piston operating within each of said cylinders, one part of each of said pistons having a relatively greater pumping capacity and constituting the pumping section of the unit and the other part of each piston having a relatively smaller pumping capacity and constituting the metering section of the unit, aninlet passageway connecting said pumping section with a source of section in communication alternately with said liquid supply, a return passageway leading from said pumping section past said metering section to said source 01' liquid supply, an outlet passageway connecting said metering section with a point of delivery, means for reciprocating said pistons,-

means functioning in timed relation with the reciprocation of said pistons for placing the ports 01' said pumping section in communication alternately with said inlet passageway and said return passageway and for placing the ports of said metering section in communication alternately with said return passageway and said outlet passageway whereby to pump liquid from the source of liquid supply past said metering section and to withdraw a measured portion of said liquid into the metering section and direct it to said point of delivery, a valve in said return passageway between said pumping section and, said metering section, a second valve in said outlet passageway, and means responsive to the pressure of the liquid in the return passageway leading from the pumping section for opening said valves when such pressure rises to a predetermined point and for closing said valves when the pressure falls below said point.

5. A pump unit of the character described, comprising a housing, a-"barrel member rotatable therein and provided witha plurality of stepped cylinders having ports at each step, a two-part piston operating within each of said cylinders, one part of each of said pistons having a relatively greater pumping capacity and constituting the pumping section of the unit and the other part of each of said pistons having a relatively smaller pumping capacity and constituting the metering section of the unit, an intake passageway connecting one side of said pumping section to a source of liquid supply, a return passageway leading from the opposite side of said pumping section past one side of said metering section to said source of supply, an outlet passageway connecting the opposite side of said metering section with a point of delivery, means for rotating said barrel to place the ports of the pumping section in communication alternately with said inlet passageway and said return passageway and to place the ports of the metering section in communication alternately with said return passageway and said outlet passageway, and means engageable with said pistons for causing reciprocation thereof within the cylinders upon rotation of said barrel whereby to pump liquid from the source of liquid supply past said metering section and to withdraw a measured portion of said liquid into the metering section and direct it to said point of delivery.

6. A pump unit of the character described,-

comprising a housing, a barrel member rotatable therein and provided with a plurality of stepped cylinders having ports at each step, a two-part piston operating within each of said cylinders, one part or each of said pistons having a relatively greater pumping capacity and constituting the pumping section of the unit and the other part of each of said pistons having a relatively smaller pumpin capacity and constituting the metering section of the unit, an intake passage way connecting one side of said pumping section to a source of liquid supply, a return passageway leading from the opposite side of said pumping section past one side of said metering section inlet passageway and said return passageway and to place the port or the metering section in communication alternately with said return passage-, I

way and said outlet passageway, means engageable with said pistons tor causing reciprocation thereof within the cylinders upon rotation of aid barrel whereby to pump liquid Irom the source of liquid supply past said metering section and to withdraw a measured porticn of said liquid into the metering section anddirect it to said point of delivery, a valve in said return passageway between said pumping section and said metering section, a second valve in said outlet passageway, and means responsive to the pressure of the liquid in the return passageway leading from the pumping section for opening said valves when such pressure rises to a predetermined point and for closing said valves when the pressure falls below said point.

7. A pump unit or the character described, comprising a housing, a barrel member rotatable therein and provided with a plurality of stepped cylinders having ports at each step, a two-part piston operating within each or said cylinders,

one part of each or said pistons having a rela-,

way connecting one side of said pumping section to a source of liquid supply, a return passageway leading from the opposite side of said pumping section past one side of said metering section to said source oi supply, an outlet passageway connecting the opposite side or said metering sec tion with a point of delivery, means for rotating said barrel to place the ports or the pumping section in communication alternately with said inlet passageway and said return passageway and to place the ports or the metering section in communication alternately with said return Das sageway and said outlet passageway, means engageable with said pistons for causing reciprocation thereoi within the cylinders upon rotation 01 said barrel where y to pump liquid from the source or liquid supply past said metering section and to withdraw a measured portion of said liquid into the metering section and direct it to said point or delivery, a valve chamber associated with the housing and divided into two independent sections, one of said sections being interposed in the return passageway between said pumping section and said metering section and the second section being interposed in the outlet passageway, a valve means associated with each of said sections, and pressure responsive means in said first mentioned section having operative connection with both of said valve means for opening the same when the fluid pressure in said first mentioned section rises above a predetermined point and for closing the valve means to said source of supply, an outlet passageway connecting the opposite side of said metering secwhen the pressure falls below said predetermined point. J

8. A pump of the character described, comprising a housing. a barrel member rotatable thereinand provided with a plurality of cylinders, a piston operating within each of said cylinders, the closed end of each cylinder having a diameter less than the open end thereof and the piston being divided into portions corresponding in diameter to said cylinder portions, each piston at the point where the small diameter and large diameter portions join being shaped to form an annular piston head, an inclined member upon which the outer ends or the pistons are adapted to ride, spring.

means associated with each piston to hold it in contact with said inclined member, and means for positively rotating the barrel and associated parts to cause reciprocation oi the pistons within their cylinders, said housing and barrel member I having ports adapted to be moved into and out oi registration, one series of ports having communication when 31 registration with the small end of the cylinders and a second series of ports when in registration having communication with the larger end of the cylinders whereby, upon rotation of the barrel and reciprocation oi the pistons, oil will be pumped from the small end of the cylinders past the large ends and a portion thereof drawn into said large ends.

' 9. A pump of the character described, com-- annular piston head, an inclined member upon which the outer ends of the pistons are adapted to ride, spring means associated with each piston to hold it in contact with said inclined member,

means for positively rotating the barrel and associated parts to cause reciprocation of the pistons within their cylinders, said housing and barrel member having ports adapted to be moved into and out of registration, one series 0! ports having communication when in registration with the small end or the cylinders and a. second series of ports when in registration having communication with the larger end oi the cylinders, and a valve chamber associated with the housins. said valve chamber being divided into two sections, a-valve mounted within said chamber with one end thereof disposed in one section and the other end disposed in the other section, said valve having conduits communicating with both ends of the said cylinders.

10. A pump of the character described, comprising a housing, a barrel member rotatable therein and provided with a plurality of cylinders, 1

a piston operating within each 0! said cylinders, the closed end of each cylinder having a diameter less than the open end thereof and the piston being divided into portions corresponding in diameter to said cylinder portions, each piston at the point where the small diameter and large diameter portions join being shaped to form an annular piston head, an inclined member upon which the outer ends of the pistons are adapted to ride, spring means associated with each piston to hold it in contact with said inclined member, means for positively rotating the barrel and associated parts to cause reciprocation of the pis= tons within their cylinders, said housing and barrel member having ports adapted to be moved into and out of registration, one series of ports having communication when in registration with the small end of the cylinders and a second series of ports when in registration having communi cation with the larger end of the cylinders whereby, upon rotation of the barrel and reciprocation of the pistons, oil will be pumped from the small end of the cylinders past the large ends and a portion thereof drawn into said large ends, and means for adjusting the inclined member to increase or decrease the stroke or said pistons to pump more or less oil as required. 

